Review

The Skeptic's Sceptic - Part 1

Carl Sagan's The Varieties of Scientific Experience: A Personal View of the Search for God (Penguin, 2006)

Carl Sagan (1934-1996)
- ‘the world’s best-known scientist in the late twentieth century’[1] - was Professor of Astronomy
and Space Sciences, and Director of the Laboratory for Planetary Studies, at Cornell University. Sagan was an astronomer and astrophysicist well known for supporting
the ‘search for extra terrestrial intelligence’ (SETI). He was also a Pulitzer
prize-winning science communicator best known for co-writing and presenting the Emmy and Peabody award-winning 1980 PBS
television series Cosmos: A Personal Voyage, a 13-hour series seen by over 400 million people. Sagan also wrote
the science fiction novel Contact, which formed the basis of the 1997 film of the same name.[2]

Sagan was a
‘Skeptic’, an American term that tends to designate someone who is sceptical
about paranormal and supernatural truth claims, but who (so it often seems to
me at least) uncritically endorses an atheistic, naturalistic worldview. Sagan
was a founding member and Fellow of the ‘Committee for the Scientific
Investigation of Claims of the Paranormal’ (CSICOP), and a member of the Council
for Secular Humanism’s International Academy of Humanism. Sagan nevertheless resisted
the atheist label, describing himself as an agnostic and writing that: ‘There
is no necessary conflict between science and religion.’[3] He also questioned Skepticsm’s frequently
antagonistic strategy:

‘The chief difficulty I see in the sceptical movement is in its
polarization: Us vs. Them – the sense that we have a monopoly on the truth;
that those other people who believe all these stupid doctrines are morons.’[4]

However, Sagan did
argue against the intellectual rectitude and truth of theism, and is thus
lauded by many atheism-promoting groups and individuals today. For example, endorsing The Varieties of Scientific Experience, atheist Sam Harris writes:

‘An unrivalled master at communicating the breadth and beauty of
science. It is not an accident that he was also one of the 20th century’s most incisive critics of popular delusion. In The Varieties of
Scientific Experience, the transcript of Sagan’s Gifford Lectures, Ann
Drydan has unearthed a treasure. It is a treasure of reason, compassion, and
scientific awe. It should be the next book you read.’[5]

It is my
contention that Sagan’s Gifford Lectures, published to commemorate the tenth
anniversary of his death, are anything but the ‘treasure of reason’ Harris
depicts.

Sagan’s
Gifford Lectures

The
Gifford Lectures were established by the will of Adam Gifford (d. 1887) to
‘promote and diffuse the study of Natural Theology in the widest sense of the
term — in other words, the knowledge of God.’[6] These prestigious lectures (which are not necessarily either pro or anti knowledge of God), given at Scottish Universities, are often given with a view
to publication. Several of these works have become classics in the fields of theology
and/or philosophy. Past lecturers include such notables as: Arthur Balfour,
William Temple, Basil Mitchell, Richard
Swinburne, Peter van Inwagen and John Haldane. Philosopher William James
delivered The Varieties of Religious Experience as Gifford Lectures in
1900-02. Sagan’s lectures were originally delivered
under the title The Search for Who We Are, but are now released with a title that plays off this famous
predecessor.

In The
Varieties of Scientific Experience: A Personal View of the Search for
God (Penguin, 2006), Sagan’s 1985 Gifford Lectures finally see the light of
day in a handsomely presented and illustrated book. The ‘time dilation’ effect involved
is doubly telling. In the first place, given the recent vogue for vehemently
anti-religious polemics (by the ‘New Atheist’ likes of Richard Dawkins[7], A.C. Grayling,[8]et al), Sagan’s book
comes as a breath of fresh air from a time when the atheistic pole of the God debate
was a good deal calmer and more balanced than it has been of late. Sagan views theism
is an understandable intellectual mistake, but one with significant practical
benefits overall. In the second place, twenty-two years of scientific investigation
since 1985 have left many of Sagan’s scientific speculations buried under the
weight of contrary evidence.

Sagan covers
four main topics:

The significance of life on Earth given modern
knowledge of cosmology

The origin of life and the possibility of
extra-terrestrial intelligence

Natural theology (arguments for theism aside
form revelation)

Religious experience

Accordingly, I
shall divide my review into four parts, beginning with Sagan’s treatment of the
place of humanity in the cosmos.

An Epistemic
Aside

It is, however,
worth observing at the outset that Sagan embraces the self-contradictory theory
of knowledge (epistemology) that:

‘superstition is… merely belief without evidence.’ (p. 1)

If ‘belief
without evidence’ is automatically ‘superstition’, then we are all of us,
including Sagan, very superstitious. Every argument rests on logical principles
that brook no support (on pain of begging the question), and every empirically
grounded statement depends upon the assumed reliability of perceptual practices
that are likewise impossible to justify without circularity. Evidence is
important, but it is not the be-all and end-all of rationality. Indeed, one
cannot coherently celebrate the undoubted virtues of evidential arguments unless one also celebrates the virtues of appropriate belief without evidence. It
would therefore be better to say that superstition is belief despite an
overwhelming evidential case to the contrary or belief formed without
proper regard for relevant epistemic duties.

Sagan quotes
Bertrand Russell with approval, asserting that: ‘it is undesirable to believe a
proposition when there is no ground whatever for supposing it true.’ (p. 189)
In the revealing selected Q&A session a questioner sensibly asks: ‘What
grounds would you have for believing that proposition?’ (p. 249) Sagan admits
the logical flaw, but instead of retracting his epistemology, flounders on:

‘Yes. That’s a very good question that leads to an infinite regress…
So if you wish to have the statement justified in internal logic – that is, a
self-consistent closed system – obviously it cannot, because it leads to an
infinite regress. But as I was saying, it seems to me that the approach of
sceptical scrutiny commends itself to our attention because it has worked so
well in the past.’ (p. 249)

Thus Sagan
admits that his epistemology is incoherent, but instead of abandoning his
self-contradictory and self-excepting position, attempts to justify it with an
inference from pragmatic results! Thankfully for the cause of rationality, the proposition
that ‘it is undesirable to accept any belief formed without proper regard for
relevant epistemic duties’ is not merely logically consistent, but more pragmatically
useful if one’s goal is the truth rather than simply the best metaphysically
naturalistic explanation presently available.

Space is Dark
and Large, and we are Small by Comparison…

Sagan begins by
observing that most of the cosmos is dark. He equates darkness with
nothingness: ‘I stress that the universe is mainly made of nothing, that
something is the exception. Nothing is the rule.’ (p. 2) Strictly speaking,
this is incorrect, since even a dark something is very much a dark something (in this case the space-time continuum itself).

Looking at the
Solar System, Sagan announces that ‘there are four large bodies other than the
Sun’ (p. 5) and pronounces that ‘the rest is debris’ (p. 5). Unfortunately,
‘debris’ carries connotations of insignificance that are not necessarily
accurate. Suppose ten chunks of rock had fallen off a cliff (perhaps due to natural
weathering), of which five were much larger than the rest; and suppose that one
of the smaller rocks had been sculpted into a bust of Carl Sagan. Would it be
accurate to describe the sculpted rock as a ‘piece of debris’ (p. 5)? Obviously,
the answer is ‘yes’ (in one sense) and ‘no’ (in another). Likewise, whether or
not Earth is ‘debris’ depends on factors besides its size or the origin of the
material of which it is made.[9]

Sagan is soon asserting: ‘the world that we live on is a
tiny and insignificant part of a vast collection of worlds.’ (p. 11) Earth may
be tiny relative to Saturn and Jupiter, but unless significance is proportional
to size, there is no justification in this fact for the assertion that Earth is
insignificant. And significance is unrelated to size. Cars are bigger than
humans, but humans are more significant than cars. Indeed, some humans are
larger than others, but that doesn’t make them more significant. Sagan’s
implicit argument for the insignificance of Earth (and hence the insignificance
of life on Earth) is ‘size-ist’.

C.S. Lewis pointed out that although our scientific
model of creation may have changed:

‘The insignificance (by cosmic standards) of the Earth became as
much a common-place to the medieval, as to the modern, thinker; it was part of
the moralists’ stock-in-trade, used, as Cicero uses it, to mortify human
ambition.’[10]

For example, Moses Maimonides, writing in his Guide
for the Perplexed in the 12th century, wrote:

‘if man examines the universe as he understands it, he knows how
small a part of it he is… mankind and certainly all other species of living
things are naught in comparison with all of continuing existence.’[11]

In point of
fact, Earth is larger than the average sized thing in the cosmos (and people
are in the average size band, between the microscopic and the macroscopic
levels).

Earth may be but
one world in ‘a vast collection of worlds’ (p. 11), and our Sun may be ‘one of
a vast multitude’ (p. 11) – but neither are at all ‘average’. We now know that
when Sagan states that ‘the average star is in no major way different from the
Sun’ (p. 23) he is wrong. As Benjamin Wiker reports:

‘Our sun is not a typical star but is one of the 9 percent most
massive stars in our galaxy, and is also very stable. Further, the sun hits the
Goldilocks mean for life – neither too hot (like a blue or white star) nor too
cold (like a red star) – and its peak emission is right at the visible part of
the electromagnetic spectrum – the very, very thin band where not only vision
is possible but also photosynthesis.’[12]

Even if Sagan didn’t
have the scientific facts wrong here, is an average student with average looks,
average grades and average interests thereby insignificant? Just as
there is no inherent relationship between significance and size, so there is no
inherent relationship between significance and mediocrity in the mathematical
sense.

God and the
Copernican Myth of Insignificance

Sagan thinks that modern scientific knowledge that we
are not ‘in the centre of the galaxy, where things are clearly important’ (p.
24) has negative implication for theism (although quite what the implication is
meant to be is never spelt out). According to Sagan, Earth is:

‘somewhere out in the galactic boondocks, the extreme suburbs, where
the action isn’t. We are situated in a very unremarkable, unprepossessing
location in this great Milky Way Galaxy.’ (p. 24)

The implicit argument here seems to be something like
this: the belief that humans are significant is a corollary of theism that is,
somehow, falsified by the empirical observation that we don’t live in the
centre of the cosmos. This ‘somehow’ is to be cashed out as the principle that
significance is related to location (that the ‘centre of the galaxy’ is ‘where
things are clearly important’) and that our failure to inhabit this central location
therefore implies our lack of metaphysical significance, and thereby entails
that theism is false.

Sagan presents us with a lovely turn of phrase, but a
terrible argument that suffers from multiple problems. For instance, as far as
we know we are the only action in the cosmos, at least as far as
intelligent life goes, and hence, by definition, the action is wherever we are.
We are not in the centre of the Galaxy. Therefore, the action is not in
the centre of the galaxy. It’s here. In other words, all the available
evidence is against the principle that significance is related to the
centrality of one’s location in space.

It should be obvious that the link between location and
significance presupposed by Sagan’s argument is non-existent. Is someone
standing in the middle of a room necessarily more important than someone
leaning against one of the walls? Is the centre of a sphere more important than
its surface? The importance of a thing has nothing to
do with its spatial position. As Keith Ward writes: ‘It does not follow that,
just because we are not physically at the centre of the universe, we are not
central to God’s plans.’[13]

The picture of the cosmos developed by the ancient
Greeks (principally Aristotle and Ptolemy) had Earth in the middle being
circled by a series of nested, concentric spheres containing the planets and
the stars. At first this model was a good fit with the available evidence. Over
the years various observations were made that didn’t fit this model, but which
could be made to fit by adding circles within circles (called ‘epicycles’) in
order to obtain ever more complex and accurate movements from the heavenly
bodies. Eventually, astronomers like Copernicus (1473–1543) argued that the old
model was needlessly complicated, and that it was simpler to suppose that the
Earth and the other planets were orbiting the Sun. This shift, from a model
with Earth at the centre to one with the Sun at the centre, is known as ‘the
Copernican revolution’.

Ironically, Sagan’s ‘locationist’ argument actually
depends upon a false metaphysical principle relating significance to location,
a principle skeptics like Sagan miss-attribute to the Christians who opposed
the Copernican Revolution, a principle that the Christians who made the
Copernican Revolution would not have accepted, but which Skeptics themselves apparently
believe (at least when presenting arguments again theism). In the
pre-Copernican scheme of things, the centre of the universe was seen more as
the dumping ground at the bottom, rather than the nerve-centre at the heart of
the universe. Sagan is wrong to think of the Ptolemaic view regarding Earth as
a universal high point that Copernicus reduced to lowly insignificance. As philosopher Robert C. Koons argues:

‘It is sometimes thought that our displacement from the centre of
the universe by Copernicus somehow contradicted at least Christian theism. But
this seems to be based on the erroneous assumption that everything believed by
ancient Christians was taken by them as equally essential to their theology.
Ancient Christians knew that the earth was spherical and that the universe is
immensely large compared to the earth. And although they all believed (until about
the fourteenth century) that the earth was the centre of the universe, they did
not think that there was anything special about being there, since it was hell,
rather than the terrestrial surface, that lay at the very centre. From the
ancient perspective, it was the periphery of the cosmos, and not the centre,
that took pride of place. The outermost sphere was the source of all
terrestrial life and motion. The centre was a kind of sump in which all that
was gross and base settled.’[14]

Nancy Pearcey and Charles Thaxton explain:

‘in medieval cosmology the centre of the universe was not a place of
special significance. Quite the contrary, it was the locus of evil. At the very
centre of the universe was Hell, then the earth, then (moving outwards from the
centre) the progressively nobler spheres of the heavens. In this scheme of
things, humanity’s central location was no compliment, nor was its loss a
demotion. In fact, in Copernicus’s own day a common objection to his theory was
that it elevated mankind above his true station. In medieval cosmology,
human significance was rooted not in the earth’s central location but in the
regard God shows toward it. Hence the idea that Copernican theory threatened
the Christian teaching of human significance is an anarchronism.’[15]

For example, Galileo, through his literary mouthpiece
(Salvati) argued that the Copernican revolution actually promoted humanity:

‘we seek to ennoble and perfect [the earth] when we strive to make
it like the celestrial bodies, and, as it were, place it in heaven, from which
your philosophers [i.e. Aristotle] have banished it.’[16]

Indeed, Sagan flatly contradicts his own Copernican
argument against theism. Under the pre-Copernican scheme, Sagan observes that
‘The Earth… had all the corruption of the universe localized here.’ (p. 36);
and yet in the very next paragraph Sagan asserts that in the Copernican
scheme: ‘the Earth was demoted.’ (p. 36)

Sagan contradicts his Copernican argument in another way
as well, in the very act of attempting to push the supposedly sharp blade of
his argument deeper into the heart of theism:

‘there was the hope that, well, at least maybe our galaxy was at the
centre of all the other galaxies, all those many billions of other galaxies.
But modern views have it that there is no such thing as a centre of the
universe…’ (p. 37)

Do you see what is going on here? In the first sentence
Sagan invokes the (false) principle that significance is related to location,
and that centrality equals significance whereas non-centrality equals
insignificance. He thereby implies that we are insignificant because not
even our galaxy is in a central location. In the second sentence Sagan
informs us that: ‘there is no such thing as a centre of the universe’. But if
there is no central location in the universe then there cannot possibly be any
non-central location in the universe! Sagan says:

‘one of the central points of special relativity is that there are
no privileged frames of reference, that we are not in an important position or
state of motion.’ (p. 40)

But if there are ‘no privileged frames of reference’,
then not only is the concept of an ‘important’ or ‘privileged’ position incoherent, so is the concept of a non-important or under-privileged position!

Contemporary science actually stands Sagan’s ‘Copernican’
objection on its head; for we now know that the great age, and hence size of
the universe in comparison with Earth, as well as the non-central solar and
galactic location of Earth, are just some of the many finely-tuned physical
preconditions for the existence of life that make the here and now of planet
earth very special indeed.[17]

The Galileo Affair

Talking of Galileo (as we were a little while back), when
Sagan comments that ‘The Catholic Church threatened Galileo with torture is he
persisted in the heresy that it was the Earth that moved and not the Sun and
the rest of the celestrial bodies’ (p. 37-38), he is invoking a myth beloved by
skeptics. Galileo’s problems with the Catholic inquisition stemmed not so much
from a conflict between ‘science’ and ‘faith’ as from a conflict of
personalities on the one hand, and a conflict with the scientific mainstream of
his day on the other.

In the first place, historian of science Ronald Numbers
explains that Galileo: ‘had gone out of his way to
insult the Pope [Urban VIII],
who had previously supported him. He put the Pope’s favourite argument against
heliocentricism into the mouth of the character Simplicio - the simple-minded
person’[18] in his Dialogue on the Great World Systems. As J. Bronowski comments:
‘It may be that the Pope felt Simplicitus to be a caricature of himself;
certainly he felt insulted.’[19] As a result Galileo:

‘was summoned down to Rome by the Inquisition [and] lived in the
Tuscan palace. And then when he was asked to move into the Vatican, to the palace of the Inquisition, one of the officials in the Inquisition vacated his
three-room apartment so that the distinguished guest, Galileo, could have a
nice apartment. And they allowed him to have his meals catered by the chef at
the Tuscan embassy. Ultimately, he was under house arrest in his villa outside
of Florence… for his theological heresies, not for his Copernicanism. He
happened to be a Copernican, but that’s not what got him into trouble.’[20]

In the second place, as Steve Fuller recounts:

‘Galileo, that 17th century icon of scientific heroism,
overplayed his hand by fabricating experimental results and embellishing
observational accounts… Even Galileo’s most sympathetic critics found his
appeal to the telescope as a scientific instrument rather puzzling. He lacked
any principled explanation – a theory of optics – for how this Dutch toy,
essentially a spyglass, enabled him to see lunar craters and sunspots.
Moreover, the lenses that Galileo improvised for his own telescope were so full
of distortion that observers not already convinced of his interpretation could
make little sense of what they saw through them.’[21]

While the Catholic church of the period certainly doesn’t
come out of the Galileo incident smelling of roses, the ‘science’ verses
‘faith’ portrayal of the affair beloved by Sagan et al is historical
revisionism plain and simple.

Is Earth Just
‘One of Many’?

According to Sagan, the Copernican revolution threatens belief in
human significance by opening up the way for doubt about the Earth being the Earth:

‘You
know the phrase… the world, or the Earth. What is the definite
article saying? It’s saying there is only one. And that goes straight back to
pre-Copernican times… if Copernicus were right, then the earth would be
demoted, no longer the Earth, the World, but just a world, an earth, one of many.’ (p. 36-37)

Of course, the mere existence of other planets (something we have
known about for a rather long time – in our own solar system at least) does not
mean that the Earth is not a special, or an unusual place. The Earth is still,
to the best of our knowledge, the Earth. Show me another! Unfortunately,
the philosophical belief that Earth is not special in any way, a belief
accepted and in no small part propagated by Sagan, continues to warp scientific
investigation of the cosmos and the presentation such exploration receives in
the media.

A ‘New Earth’?

On Wednesday April 25th 2007 various news media made a song and dance over the discovery of Gliese 581c:

‘a planet outside our
solar system that is potentially habitable, with Earth-like temperatures, a
find researchers described Tuesday as a big step in the search for “life in the
universe.”’[22]

However,
a big step does not a completed journey make. Just how ‘habitable’ is
‘habitable’, and just how ‘Earth-like’ is ‘Earth-like’? Well, as Seth Bornenstein of the associated press admitted:
‘There’s still a lot that is unknown about the new planet, which could be
deemed inhospitable to life once more is known about it...’[23] Borenstein observed:

‘it’s worth noting that
scientists’ requirements for habitability count Mars in that category: a size
relatively similar to Earth’s with temperatures that would permit liquid water.
However, this is the first outside our solar system that meets those
standards.’[24]

Of
course, as far as we know, Mars is lifeless (at best it may support some
bacteriological life – life that may have transferred there from Earth).
Moreover:

‘Based on theory, 581c
should have an atmosphere, but what's in that atmosphere is still a mystery
and if it's too thick that could make the planet's surface temperature too hot...
“You need more work to say it’s got water or it doesn’t have water,”
said retired NASA astronomer Steve Maran,
press officer for the American Astronomical Society...’[25]

Gliese 581c (in the constellation of Libra)
has an orbit that would permit liquid water if there is H2O
and if it has the right sort of atmosphere. David Charbonneau of the Harvard-Smithsonian Center for Astrophysics in Cambridge Massachusetts comments:

‘If the planet
is a rocky super-Earth, then perhaps it has a surface with liquid
water and life… If instead the planet is a “sub-Neptune”, then it would
have a large gas envelope that buries the surface below, making it inhospitable
for life.’[26]

As Sara Seager, a planet expert at the Massachusetts
Institute of Technology, said: ‘if the planet had an atmosphere more
massive than Venus’, then the surface would likely be too hot for liquid water.”’[27]

‘The New Earth - does
the discovery of a planet just like ours means there IS life out there?’

This is tabloid sensationalism. The third planet orbiting Gliese 581 is not ‘just like ours’ and
does not qualify as a ‘new earth’. The article by Daily Mail science editor Michael Hanlon is a
little more down to earth (if you’ll excuse the pun), because it does put in
some qualifications, such as that this is:

‘possibly the
most extraordinary world to have been discovered by astronomers... The
Earth-like planet that could be covered in oceans and may support
life... It probably has a substantial atmosphere and may be
covered with large amounts of water - necessary for life.’[28]

Nevertheless,
the tone of the article is so upbeat that only
careful readers are likely to spot the true significance of the occasional
‘could’ and ‘may’. Large print announces: ‘evidence that life - just
like us - might be out there.’[29] However, the simplistic leap from ‘there may be
water’ (given the right sort of atmosphere) to ‘there may be life’ flies
in the face of all the evidence. Water is necessary for life, but (as we’ll see
in Part II) there’s a lot more to life than water! Hanlon does at least admit: ‘If there is life
there it would have to cope with the higher gravity and solar radiation from
its sun’, and that: ‘Just because Gliese 581c is habitable [which can mean being like Mars] does not mean that it is
inhabited.’[30]

While the Daily Mail may be thinking in terms of
life ‘just like us’, even those scientists who think there may be life on 581c
are generally thinking in terms of microbial life. In point of
fact, there is currently a lack of the evidence we’d expect if 581c was
inhabited by a technologically advanced civilization: ‘According to Seth Shostak, of the Search for Extraterrestrial
Intelligence Institute in California, the Gliese system is now a prime target for a radio search. “We had actually looked at
this system before but only for a few minutes. We heard nothing…”’[31] What if we look again and
still find nothing? Will this count as evidence against the philosophical assumptions
about an easy origin of life and evolution of intelligent life that underpin much SETI
research? After all, this is the best candidate for ET’s home so-far discovered: ‘its sun is an
ancient star - in fact, it is one of the oldest stars in the galaxy, and
extremely stable. If there is life, it has had many billions of years to
evolve.’[32] On this point, it is interesting to note Hanlon admitting:

‘We don’t understand how
life began on our world, let alone how it could arise anywhere else. There may
be an awful lot of bugs and bacteria out there, and only a few worlds with what
we would recognize as plants and animals. Or, of course, there may be nothing.’[33]

If we
don’t understand how life began (within a non-teleological framework), then it
is surely premature to be making statements about
life on 581c supported by nothing besides the possibility that there may be liquid water there, if it doesn’t have the wrong sort of atmosphere!

Darwinist
Nick Matzke cautions:

‘A planet that massive
might have the problem of being so smooth it has a global ocean, which probably
would make it tough to produce the concentration mechanisms (evaporation in
pools etc.) that might be required for the origin of life…’[34]

Astronomer
Guillermo Gonzalez is similarly downbeat concerning the chances of life on Gliese 581c:

‘the host star being an
M dwarf [poses] problems for habitability. The smallest planet’s eccentricity
is comparable to that of Mercury, so it is probably locked into a 3:2
spin-orbit resonance. So [581c] will experience large temperature variations
over the course of its orbit. What’s more, because its rotation is slower, it
should have a weaker magnetic field and be subject to enhanced solar wind
stripping of its atmosphere. Finally, the fact that it has a mass at least 5x
Earth’s means that it will have a high surface gravity and less surface relief
than the Earth - meaning no dry land.’[35]

Gliese 581c is the first non-Gas giant discovered within the
so-called ‘goldilocks’ zone of
‘habitable’ orbits around its star. Hence it might have a temperature
in the right ‘goldilocks’ zone,
depending on what the atmosphere is like. If it does have the right
temperature, then it mighthave
liquid water, which is another necessary condition for life. However, the recipe for life is more
complicated than ‘a big rock, liquid water and a star plus time’; and even if
581c has liquid water, it suffers from several habitability drawbacks
(including large temperature variations, inadequate shielding against the solar
wind from its M dwarf star that would strip away its atmosphere, and high
gravity[36]). More recently:

‘simulations
of the climate on Gliese 581c created by Werner von Bloh of the Institute for
Climate Impact Research in Germany and his team suggest the planet is no
Earthly paradise, but rather a faraway Venus, where carbon dioxide and methane
in the atmosphere create a runaway greenhouse effect that warms the planet well
above 212 degrees Fahrenheit (100 Celsius), boiling away liquid water and with
it any promise of life.’[37]

Serious Odds

Astronomer Hugh Ross lists 200 parameters required for a
life-bearing planet. Comparing the chances of a planet falling within all of
these parameters by chance alone with our best estimate of the total number of
planets in the universe (1022) he estimates that there is ‘less than
1 chance in 10215’ of even one habitable planet existing in the
universe.[38] Elsewhere, Ross argues:

‘fewer
than a trillionth of a trillionth of a percent of all stars will have a planet
capable of sustaining advanced life. Considering that the observable universe
contains less than a trillion galaxies, each averaging a hundred billion stars,
we can see that not even one planet would be expected, by natural processes
alone, to possess the necessary conditions to sustain life.’[39]

Offering ‘a revised Drake equation’ for calculating the number of
intelligent civilizations in our Galaxy (more about the ‘Drake equation’ in
Part II), astronomer Guillermo Gonzalez and philosopher Jay W. Richards
conclude:

‘the
probability that the Milky Way Galaxy contains even one advanced civilization
is likely to be much less than one. This is an interesting result, of course,
since we exist.’[40]

Astrobiologists Peter D. Ward and Donald Brownlee agree:

‘If
some god-like being could be given the opportunity to plan a sequence of events
with the express goal of duplicating our “Garden of Eden”, that power would
face a formidable task. With the best intentions, but limited by natural
laws and materials, it is unlikely that Earth could ever be truly
replicated.’[41]

The fact that we
exist, then, naturally suggests the hypothesis that the causes of our existence
were not limited to natural laws and materials.

Burnt to a
Crisp?

Looking forward,
Sagan predicts that the Earth will one day be burnt to a crisp by the aging sun
as it expands, and he suggests that this negative implications for the belief
that humans were created on purpose:

‘Some 5 or 6 or 7 billion years from now, the Sun will become a red
giant star and will engulf the orbits of Mercury and Venus and probably the
Earth… it is not our most pressing problem. But it is something to bear in
mind. It has theological implications.’ (p. 20.)

Presumably the
underlying thought here is that if life on Earth is special to its Creator then
the Creator surely would not allow it to be extinguished, and that since it
would seem that life on Earth will be extinguished in a few billion years time,
the obvious conclusion it that life on Earth is not in fact special to its
Creator, perhaps because it doesn’t have one after all. However, neither
conclusion is at all obvious. Indeed, I’m not convinced that such an event
would have any theological implications – unless one thinks that biblical
Christianity predicts that humans never settle off-world. But nor am I
convinced that such an event will happen.

Of course, such
an event will happen if the universe continues to exist (and to run
according to the known laws of physics) for long enough. But whether or not the
universe does that is, for the theist, something very much in the hands
of its Creator, who is thought by them to sustain the universe in existence
from one moment to the next. Hence, if one does think the bible predicts that
people will not leave Earth before the creation of ‘the new heavens and earth’,
one would then be left pitting one inference (to the conclusion that God will
bring cosmic history to an end before 5-7 billion years are up) against another
inference (that God will not bring cosmic history to an end before 5-7 billion
years are up). As Sagan writes in the similar context of the possibility that
humanity will destroy itself in a nuclear war:

‘we would have to conclude either (a) than an omnipotent and
omniscient God did not create the universe, that is, that He was an inexpert
cosmic engineer, or (b) that human beings will not self-destruct. Either
alternative, it seems to me, is a matter of some interest, would be worth
knowing.’ (p. 59)

Sagan’s reason
for preferring the anti-Christian (though not exactly anti-theistic) fork of
this dilemma, that ‘there is a dangerous fatalism lurking here’ (p. 59), is
plainly question-begging. If Christianity entails that humanity as a
species will not destroy itself, or be destroyed, then accepting this
prediction would constitute a ‘dangerous fatalism’ (one that might lead to our
destruction) only if Christianity is not true. Besides which, multiple
forms of self-interest would surely mitigate against Sagan’s (hypothetical)
‘dangerous [optimistic] fatalism’, since this does nothing to guarantee
individual, or familial, or national, or racial survival.

It will be a
long time before we are in a position to empirically demonstrate which
prediction - that God will bring cosmic history to an end before 5-7 billion
years are up or that that God will not bring cosmic history to an end before
5-7 billion years are up - is correct. Besides which, the latter prediction
admits of multiple interpretations; ranging from the reading of scripture
requiring the predicted cap to cosmic history simply being mistaken, to
Christianity’s being false, through to Atheism being true. Since we’re
currently 5-7 billion years off even needing to debate which of these
interpretations is the most plausible, I think we can afford to let sleeping
dogs lie.

Conclusion

In Part I of
this review we have seen that Sagan invests in arguments to the effect that
modern scientific knowledge should disabuse us of the theistic notion that
humans and the planet we inhabit are special or significant parts of the
cosmos, and should thereby disabuse us of any theistic belief which entails
that humans are significant in the sight of God. Each and every one of these arguments
is based upon implausible philosophical claims - such as that metaphysical
significance is related to physical size or location.

Moreover,
advances in scientific knowledge since 1985 have shown that several of Sagan’s
empirical premises (such as that the Sun is an average star) are simply incorrect.
Indeed, Sagan himself explicitly affirms scientific views that undermine his
argument from the ‘non-centrality’ of the Earth in the cosmos (i.e. that there
is no ‘centre’ of the cosmos).

Finally, the exact
same evidence that Sagan seeks to use in establishing the insignificance of
life on Earth (e.g. Earth’s life-crucial non-central location in our galaxy) actually
justify a multi-factorial ‘anthropic principle’ that many see as grounding a
strong argument to precisely the opposite conclusion.

The same report mentions the
possibility that atmospheric conditions on Gliese 581d might result in a
greenhouse effect that brings its temperature within the range required for
liquid water, despite the planet orbiting outside the ‘Goldilocks Zone’
inhabited by Gliese 581c. Of course, there may not be any water on 581d.
Moreover, 581d suffers the drawback of being even more massive than 581c, at
eight times the mass of Earth.